1. Technical Field
The present invention relates to a method for discharging a liquid containing a biological material, and a microarray manufacturing method using such a dispense method. More specifically, the invention relates to a dispense method that can improve dispense stability when a liquid containing a biological material is dispensed using an inkjet system, and a microarray manufacturing method using such a dispense method.
2. Related Art
DNA microarrays (DNA chips) have been utilized as a technique for monitoring gene expression patterns or screening new genes. Meanwhile, protein microarrays (protein chips) for use in protein analysis have also been being developed lately using the same technique used in DNA microarrays. Microarrays can be manufactured by spotting a sample solution containing a biological material such as DNA or proteins densely onto a substrate such as a glass slide. Known examples of this sample solution spotting method are one using contact pins, and one using an inkjet system, for example, as disclosed in JP-A-11-187900.
The inkjet system has an advantage in that it enables creating a stable spot shape quickly and also enables preparing high-density microarrays by narrowing the nozzle pitch.
A droplet discharging head is used in the manufacture of microarrays utilizing the inkjet system. In terms of reducing the manufacturing cost, etc., the droplet discharging head needs to be able to be used repeatedly by being refilled with the sample solutions. Particularly, if multiple kinds of biological materials are used to manufacture a microarray, the droplet discharging head needs to be able to achieve good dispense performance even after it has been washed inside and refilled with a new liquid.
However, when a biological material readily adsorbed to a solid-phase surface, such as proteins, is used as a sample solution, the biological material may be adsorbed to the inner walls of the droplet discharging head, and cannot be removed even by washing the inside of the droplet discharging head, which might cause significant change in channel performance and result in a deterioration in dispense performance.